Abstract

Increasingly tighter regulations regarding organic waste, and the demand for renewable chemicals and fuels, are pushing the manufacturing industry toward higher sustainability to improve cost-effectiveness and meet customers’ demand. Food waste valorization is one of the current research areas that has attracted a great deal of attention over the past few years as a potential alternative to the disposal of a wide range of residues in landfill sites. In particular, the development of environmentally sound and innovative strategies to process such waste is an area of increasing importance in our current society. Landfill, incineration and composting are common, mature technologies for waste disposal. However, they are not satisfactory to treating organic waste due to the generation of toxic methane gas and bad odor, high energy consumption and slow reaction kinetics. In fact, research efforts have also been oriented on novel technologies to decompose organic waste. However, no valuable product is generated from the decomposition process. Instead of disposing and decomposing food waste, recent research has focused on its utilization as energy source (e.g., for bioethanol and biodiesel production). Organic waste is also useful to generate useful organic chemicals via biorefinery or white biotechnology (e.g., succinic acid and/or bio-plastics). This article is aimed to summarize recent development of waste valorization strategies for the sustainable production of chemicals, materials, and fuels through the development of green production strategies. It will also provide key insights into recent legislation on management of waste worldwide as well as two relevant case studies (the transformation of corncob residues into functionalized biomass-derived carbonaceous solid acids and their utilization in the production of biodiesel-like biofuels from waste oils in Philippines, as well as the development of a bakery waste based biorefinery for succinic acid and bioplastic production in Hong Kong) to illustrate the enormous potential of biowaste valorization for a more sustainable society. Future research directions and possible sustainable approaches will also be discussed with their respective proofs of concept.

Abstract

While gathering information about oil transportation for VTT Publication 547, Oil transportation and terminal development in the Gulf of Finland (2004), the question about other harmful substances transported in liquid bulk was raised. The Finnish Ministry of the Environment, Finnish Environment Institute (SYKE) and Finnish Maritime Administration (FMA) have made it possible for us to continue the work on tanker transportations by financing this study. The area has been widened to cover the entire Baltic Sea. This publication introduces the statistics concerning the chemicals handled in liquid bulk in the Baltic Sea ports in 2004. The data is based on the public registers, data files and announcements of port authorities and operators. A special questionnaire on transported chemicals, and specifically on bulk form chemicals, was made for ports. Some of the ports have expressed their concern about giving what they consider to be sensitive information; alas, the data in this publication is not to be considered full and complete, but it does give an indication of where chemical tankers are sailing. The latest comprehensive study about chemical transportations in the Baltic Sea was made by HELCOM in 1990 (Study of the Risk for Accidents and the Related Environmental Hazards from the Transportation of Chemicals by Tankers in the Baltic Sea Area). HELCOM statistics were gathered by a thorough collection of data in all Baltic Sea ports during the entire year of 1987. Unfortunately, this specific and time-consuming means of data acquisition was impossible with this publication due to the time scale of the project. Some of the most dangerous or most common chemicals were selected and briefly analysed on the basis of their environmental impact if released into the water. The risk of chemical outflow has also been discussed within the collision and grounding modes. A special chapter related to the Northern Baltic waters has been written on the risk of winter navigation for chemical transportation. Discussion has also been carried out on the fate of chemicals spilled on water and on the physical fundamentals when trying to control them; finally, some scenarios are presented on potentially high-risk areas. Marine chemical transportation is constantly growing in regard of the number of chemicals and the total volume of goods transported. Today, the number of different substances and compounds is quoted in thousands. A great many of these chemicals are dangerous to the environment, and even though the risk of a chemical accident is considered small due to very high standards regarding safety, it does exist. Even if chemical tankers do take safety aspects into consideration, there are a number of other ships in the same sea area, as well as a number of ships crossing their paths and meeting each other in narrow sounds or in dense traffic areas. The safety practices of chemical tankers are among the best. Maritime society has also introduced several new actions to improve maritime safety. It is a well known fact that the number of large scale oil and chemical spills has declined during the last decades. This fact shows that recent measures such as phase out of single hull tankers, stricter legislation, IMO actions, Erika packages, etc. have improved the safety of ships and routes. However, around 80% of all incidents and accidents are due to the human factor, for example human/machine interaction or cultural behaviour. Thus even though new technical means (VTS, AIS, ECDIS, etc.) have been established to improve safety, there is a lot of work to be done to prevent accidents and environmental damage.